Since an LED light is working at a constant current working state, when the current of the LED light is constant, a voltage of the LED light could have a certain deviation, thus in a traditional LED backlight driving power source, it is always adopting a constant-current driving source to drive the LED backlights. Shown as FIG. 1, an existing backlight driving method is always outputting a DC after transformed by an AC-DC module, before ensuring a constant-current output for an LED lightstrip through raising or lowering the voltage by a DC-DC module. Since there are two steps of transformations needed from an AC source to the LED lightstrip, (that is, transforming from AC to DC, then from DC to DC), it causes a low efficiency for the transformation. Also, a DC-DC processing section needs a plurality of power components (a power switch circuit and a control circuit) with a plurality of corresponding topologies, which causes a relatively high cost.
Therefore, the current technology needs to be improved and developed.